Not Applicable
The present invention relates generally to the field of apparatus and methods for sealing wounds in the blood vessels of humans or animals. More specifically, the invention relates to a guided vascular compression device for percutaneously sealing arterial or venous punctures subsequent to surgical procedures, by promoting in situ hemostasis.
A large number of medical therapeutic and diagnostic procedures of involve the percutaneous introduction of instrumentation into a vein or artery. For example, percutaneous transluminal coronary angioplasty (PTCA), most often involving access to the femoral artery, is performed hundreds of thousands of times annually, and the number of other such vessel-piercing procedures performed, e.g., percutaneous coronary angiography and atherectomy, has exceeded two million per year.
In each event, the closing and subsequent healing of the resultant vascular puncture is critical to the successful completion of the procedure. Traditionally, the application of external pressure to the skin entry site by a nurse or physician has been employed to stem bleeding from the wound until clotting and tissue rebuilding have sealed the perforation. In some situations, this pressure must be maintained for half an hour to an hour or more, during which the patient is uncomfortably immobilized, often with sandbags and the like. With externally applied manual pressure, both patient comfort and practitioner efficiency are impaired. Additionally, a risk of hematoma exists since bleeding from the vessel may continue until sufficient clotting effects hemostasis. Also, external pressure devices, such as femoral compression systems, may be unsuitable for patients with substantial amounts of subcutaneous adipose tissue, since the skin surface may be a considerable distance from the vascular puncture site, thereby rendering skin compression inaccurate and thus less effective.
More recently, devices have been proposed to promote hemostasis directly at the site of the vascular perforation. One class of such puncture sealing devices features intraluminal plugs, as disclosed in U.S. Pat. No. 4,852,568xe2x80x94Kensey; U.S. Pat. No. 4,890,612xe2x80x94Kensey; U.S. Pat. No. 5,021,059xe2x80x94Kensey et al.; and U.S. Pat. No. 5,061,774xe2x80x94Kensey. This class of device is characterized by the placement of an object within the bloodstream of the vessel to close the puncture.
Another approach to subcutaneous puncture closure involves delivery of tissue adhesives to the perforation site, as disclosed in U.S. Pat. No. 5,383,899xe2x80x94Hammerslag. Some likelihood exists of introducing the adhesive so employed disadvantageously into the bloodstream. U.S. Pat. No. 4,929,246xe2x80x94Sinofsky discloses the concept of applying pressure directly to an artery, and relies on the directing of laser energy through an optical fiber to cauterize the wound.
Yet another proposed solution to obviate the reliance on skin surface pressure is disclosed in U.S. Pat. No. 5,275,616xe2x80x94Fowler, wherein a cylindrical plug is inserted along the shaft of a catheter segment extending from the skin surface to the blood vessel. The catheter is then removed so that the plug can expand as fluid is drawn into the plug from the vessel and surrounding tissue. Unless pressure is applied, however, bleeding may occur around the plug into the subcutaneous tissue. Another approach that similarly deposits a plug into the tissue channel is disclosed in U.S. Pat. No. 5,391,183xe2x80x94Janzen et al., which discloses a variety of plug delivery devices including threaded plug pushers and multilegged channels. As in the other disclosed methods for introducing a foreign plug into the incision, the Janzen et al. plug material, generally resorbable, is not removed from the patient once installed. Such permanent placement of foreign material into the body may result in inflammation or scar formation in the long term.
Furthermore, many of the prior art devices rely on tactile sensation alone to indicate to the surgeon the proper placement of the puncture closing instrumentation, and may require upstream clamping of the blood vessel to reduce intraluminal pressure to atmospheric at the puncture site.
As the foregoing description of the prior art demonstrates, none of the heretofore proposed solutions fulfills the need for a relatively simple, non-cautery apparatus and method for subcutaneously applying pressure directly to the vicinity of the vessel puncture by means of a pressure element that is removed from the patient once sealing of the puncture is achieved. There is a further need for a puncture sealing system that features use of instruments already in place at the access site so that the position for possible reentry is not lost, and the time required for the physician to change instrumentation is minimized. There is a still further need for a system that maintains pressure on the puncture site by lightweight mechanical means, thereby relieving the patient from the discomfort of external compression means, and freeing hospital personnel from constant surveillance of cumbersome external pressure structures for the duration of the hemostasis. There is also a need for a hemostatic device that can be effectively employed regardless of the thickness of the tissue between the skin and the puncture site, by applying localized pressure close to the puncture site, rather than remote, diffused pressure to the skin surface.
It is an object of this invention to provide a method and apparatus for sealing post-surgical vascular punctures that overcome the foregoing deficiencies.
It is a further object to apply pressure directly to the vicinity of the vascular puncture access site utilizing a subcutaneous pressure element that is removed permanently from the patient once hemostasis is achieved.
It is another object to employ an introducer instrument already in place at the access site to minimize instrumentation changing time, and to maintain access during an initial clotting period to facilitate possible reentry.
It is yet another object to maintain adequate hemostatic pressure on an adipose or fatty tissue layer above the puncture site in order to close the puncture naturally, to reduce the potential for pseudo-aneurysm formation, and to maintain such pressure by lightweight, non-labor intensive, mechanical means, thereby reducing patient discomfort.
The present invention involves a method for sealing a puncture site in a blood vessel, and apparatus for performing that method, wherein use is made of an introducer sheath (commonly referred to in the medical community as an xe2x80x9cintroducerxe2x80x9d) which is usually already in place inside the puncture site when a medical practitioner has completed a procedure that requires intravascular access. Locator means, preferably either a locator tube (having an inflatable locating balloon), or a standard guidewire, is passed through the introducer and into the lumen of the vessel. Alternatively, a dissolvable locating tip can be provided at the distal end of the catheter. The locating tip is inserted into the lumen of the vessel, using a guidewire, and maintains the distal end of the catheter in its proper position in the puncture site.
SCA semi-rigid catheter, including an expandable compression element at its distal end, and either two axial lumens (used in a compression balloon embodiment) or a single axial lumen (used in other embodiments), is inserted along the locator means fully into the introducer so that the expandable compression element at the distal end of the catheter is contained in an unexpanded state within the distal end of the introducer when the introducer is in a first or distal position relative to the catheter.
The introducer and the catheter are partially withdrawn together (moved proximally) from the puncture site until a preferred location above the vessel is achieved, the relative axial positions of the introducer and the catheter remaining unchanged, so that the introducer remains in its first or distal position relative to the catheter. This location is chosen to provide for a layer of fatty tissue above the puncture site between the compression element and the vessel. The extent of partial withdrawal is determined by the tactile sense of the practitioner, aided by a marker on a locator tube. for the embodiment employing a locating balloon as the locator means, or by fluoroscopic viewing of a contrast medium, for the embodiments employing a guidewire (with or without a dissolvable locating tip) as the locating means.
When the location is achieved, the introducer is moved to a second or proximal position relative to the catheter until the expandable compression element is revealed and expanded to bear on the fatty tissue layer.
In another embodiment, the expandable compression element comprises an expandable prong assembly including a resilient spanning sheet for compressing the fatty tissue layer. In still another embodiment, the expandable compression element comprises a foam pad element bearing directly on the fatty tissue layer upon expansion when deployed from the introducer.
Once the compression element (balloon, prongs or foam tip) is in place, a lightweight holding arrangement is employed to maintain hemostatic pressure. The holding arrangement comprises an adhesive skin patch and fastener strips or bands bringing downward pressure on a sheath cuff clamped to the introducer. After an initial period of hemostasis, (approximately one to five minutes), the locator means (locator balloon tube or guidewire) is removed from the puncture and the apparatus. After another five to twenty-five minutes of pressure on the puncture, the expandable distal end element (compression balloon, prongs or foam) is collapsed, and the introducer and catheter are permanently removed from the patient.
These and other features and advantages of the present invention will be more readily apparent from the Detailed Description that follows.